Trivia

Before they shot the movie, four actresses spent a day at the house together to get familiarized with the layout of the house and get comfortable with each other. They cleaned the house, weeded the garden, cooked meals and ate together. They also fixed the shoji screen, which Koreeda liked it so much that he incorporated the scene in the movie.

Koreeda felt the house was a central part of the story. After extensive search, they found the house in Kita Kamakura. They were just going to use only the gate and out side of the house. But when they saw front entrance, yard and rest of the house, Koreeda felt sets wouldn't reflect the reality and soul of the house. They asked the owner of the house for permission to use the entire house including everything in the house as they are. Only set they recreated was the kitchen when Sachi and Yoshino cooking noodles. The owner even gave them a permission to mark the wooden post Sachi marked Suzu's height.

Koreeda's Non-Script: In previous movies he made, he did not give script to child actors. He just mouthed the dialogue to child actors as the scene took place and the child actors repeated what Koreeda had just said, reacting to what other actors were saying and doing at that moment. It made it easier for child actor not having to memorize dialogues and helped them act more naturally. Since Suzu was not exactly a child, Koreeda gave she her a choice of either to have a script or not have one. She chose not to have a script, thinking this might be the last chance she would be able to act this way.

Suzu Hirose, who plays Suzu, had played basketball in junior high but had never played soccer. For character, Suzu, playing soccer was major part of her life. It made her feel alive, accepted, enable for her to make friends and have her own "ibashiro (a place you belong)", and be a "child". Koreeda felt it was important that Suzu played soccer well enough to put it on screen. She, along with Ohshiro Maeda, who played Futa, was assigned a soccer coach and took up soccer training close to a year. She became quite an able player many in media thought Suzu had been playing soccer for a long time. The goal scene was reshot many times, even after Koreeda was satisfied, until Suzu felt it was good enough to make spectators' cheer believable.

When Koereda first read the manga series "Umi-machi Diary", he was immediately attracted to the story which dealt with family, death and child being abandoned and felt he was the right director to bring it to film. He contacted the author but found someone already had a right to the book. Couple years later he was informed the right to the book had been withdrawn and it was his if he was still interested.